Now of course I have no idea of the rights and wrongs of this specific case. But it is apparant that the child isn't being coerced to stay.

When two officers force him to the ground to cuff him, one of the police, before knocking the camera to the ground attempts to block the father from filming the scene by waving his sheet of paper which gives him authority.

I am sure they wouldn't hesitate to do so, but I am pretty confident I'd take at least one of them with me.

Stalin used to arrest and remove parents, and just leave little children to fend for themselves (the neighbours wouldn't help them, for fear of being labelled friends of an enemy), but afaik even he never sank this low.